Engee documentation

Circuit Breaker

A single-pole switch controlled by an external signal.

blockType: AcausalElectricPowerSystems.Switches.CircuitBreaker

Path in the library:

/Physical Modeling/Electrical/Switches & Breakers/Circuit Breaker

Description

Block Circuit Breaker Simulates a single-phase circuit breaker that uses an external signal and current value to break an electrical circuit.

The table below shows how the external signal vT and the value of the parameter Breaker Behavior determine the state of the block.

Condition Block behavior Resistance used

vT < Threshold

The switch is closed. Port 1 is connected to port 2.

Closed Resistance

vT ≥ Threshold

Opens when the current crosses zero after vT ≥ Threshold (Breaker Behavior = simple)

When the current on port 1 passes through zero, this port is disconnected from port 2 (Breaker Behavior = zerocrossing). The switch is open.

Open Conductance

Opens when vT ≥ Threshold

The switch is open.

Ports

Input

vT — pass control port:q[<br>] scalar

The input port that controls the state of the switch.

~1 — electric port pass:Q[<br>] electricity

Electrical port.

~2 — electric port pass:Q[<br>] electricity

Electrical port.

Parameters

Closed resistance — resistance of the closed switch
1e−3 ohms (by default)

Resistance between ports 1 and 2 with the switch closed.

Open conductivity — conductivity of the open switch
1e−6 1/ohm (by default)

Conductivity between ports 1 and 2 when the switch is open.

Threshold, V — threshold voltage
0.5V (by default)

The threshold voltage for the control port is vT. The unit uses the value of this parameter as the value of the control signal at the beginning of the simulation to determine whether the switch is initially open or closed. If the Breaker Behavior parameter is set to zerocrossing, then when the voltage rises above the threshold value, the switch opens when the current crosses zero. If the Breaker Behavior parameter is set to simple, then the switch opens as soon as the voltage rises above the threshold value. When the voltage on the control port drops below the threshold value, the switch closes.

Breaker Behavior — the behavior of the breaker when vT rises above the pass threshold value:q[<br>] zerocrossing (by default) | simple

The behavior of the switch when the value on the control port vT is greater than or equal to the value of the parameter Threshold, V. The switch can be opened either as soon as the voltage rises above the threshold value, or when its current crosses zero at the same time.